US2584287A

US2584287A - Digging adjustment for endless type trench excavators

Info

Publication number: US2584287A
Application number: US48121A
Authority: US
Inventors: Daniel F Przybylski
Original assignee: Individual
Current assignee: Individual
Priority date: 1948-09-07
Filing date: 1948-09-07
Publication date: 1952-02-05
Anticipated expiration: 1969-02-05

Description

1952 D. F. PRZYBYLSKI 2,584,237

DIGGING ADJUSTMENT FOR ENDLESS TYPE TRENCH EXCAVATORS Filed Sept. 7, 1948 10 Sheets-Sheet 1 4 IN VEN TOR.

6&(2/2/ JQ/ rngg 1952 D. F. PRZYBYLSKI 8 DIGGING ADJUSTMENT FOR ENDLESS I TYPE TRENCH EXCAVATORS l0 Sheets-Sheet 3 Filed Sept. 7, 1948 10 Sheets-Sheet 5 Feb, ,5, 1952 D. FVPRZYBYLSKI DIGGING ADJUSTMENT FOR ENDLE TYPE .TRENCH EXCAVATORS Filed Sept. 7. 1948 D. F. PRZYBYLSKI DIGGING ADJUSTMENT FOR ENDLESS Feb. 5, 1952 2,584,287

-TYPE TRENCH EXCAVATORS V =Filed. Sept. 7, 1948 10 Sheets-Sheet 6 INVENTOR.

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Feb. 5 l952 D. F. PRZYBYLSKI DIGGING ADJUSTMENT FOR ENDLESS TYPE TRENCH EXCAVATORS .10 Sheets-Sheet '7 Filed Sept. '7 .1948

A .A u W M x H w i m k s L. Q Q 8 M80 F 1952 '0. F. PRZYBYLSKI 4, 8

DIGGING ADJUSTMENT FOR ENDLESS TYPE TRENCH EXCAVATORS Filed Sept. 7, 194a 1o Sheets-Sheet 8 III IN VEN TOR.

BY K/ I F 5, 1952 n. F. PRZYBYLSKI 2,584,

DIGGING ADJUSTMENT FOR ENDLESS TYPE TRENCH EXCAVATORS- Filed Sept. 7,..1948 1O Sheets-Sheet 9 IN VEN TOR.

Feb. 5, 1952 D. F. PRZYBYLSKI 2,584,287 DIGGING ADJUSTMENT FOR ENDLESS TYPE TRENCH EXCAVATORS Filed Sept. 7, 1948 10 Sheets-Sheet 10 l 2/2 24 g c ,2/5' z/kg 200 221 a w 5!: I 5

Patented Feb. 5, 1952 UNITED STATES PATENT orrlcs DIGGING ADJUSTMENT FOR ENDLESS TYPE TRENCH EXCAVATORS Daniel F. Przybyls ki, Winona, Minn. Application September '7, 1948, Serial No. 48,121 9 Claims. (01. 37-90) My invention relates to improvements in trench excavators, and, more particularly, to such an excavator of the ladder type.

An object of this invention is to provide a self-contained and self-propelled trench excavator;

Another object of this invention is to provide a trench excavator having a novel grade holder and crumber.

Still another object of this invention is to provide novel ram controls for the crumber.

A further object is to provide novel driving connections from an engine for operating an endless shovel chain having attached shovels.

A further object of this invention is to provide a novel hydraulic lift for a shovel boom.

Other objects of this invention willbe apparent from the following description and thefaccompanying drawings.

To the above end, generally stated, the invention consists of the novel devices hereinafter described and defined in the claims.

In the accompanying drawings, which illustrate the invention, like characters indicate like parts throughout the several views.

Referring to the drawings: 1 Figs. 1 and 2 are left-hand side elevational viewed the improved trench excavator showing, respectively, the front end portion and the rear endportion thereof;

Fig; '3 is a fragmentary detail view in plan of thejliydraulic boom lift and associated parts;

Fig. 4 is a detail view partly in side elevation and'partly in longitudinal vertical section taken on the irregular line 4-4 of Fig. 5; Fig. 5 is a plan view of the parts shown in Fig. 6 is a fragmentary detail view partly in side elevation and partly in longitudinal vertical section taken on the line 6-6 of Fig.

Figs. 7, 8 and 9 are fragmentary detail views partly in elevation and partly in section taken on the lines 1'I, 8-8, and 9-9 respectively of Fig.6;

Fig. 10 is a fragmentary view principally in planwith some parts sectioned on the line Ill-4!! of- Fig. 6;

- Fig.- 11 is a plan view of the hydraulic grade holder'beam and the underlying crumber, on the same scale as Figs. 1 and 2; g

' Figs. 12 and 13 are plan views showing, respectively, the front and the rear sections of the-shovel boom; 1

- Fig. 14 is a viewin longitudinal central section taken-on the line I l-I4 of Fig. 12,-and further showing on' the same section line the shovel con-, veyor chain guide;

Figs. 15 and 16 are detail views in section taken on the lines |5-l5 and [6-46 of Fig. 14;

. Fig. 17 is a detail view partly in elevation and partly in section taken on the line Il-l'| of Fig. 13;

Fig. 18 is a fragmentary view in side elevation showing the connected portions of the shovel boom and its head;

Figs. 19 and 20 are detail views partly in end elevation and partly in transverse section taken on the lines l9-l9 and 20-40 of Fig. 18, respectively;

Fig. 21 is a'view partly in end elevation and partly in transverse section taken on the line 2l2l of Fig. 2;

Fig. 22 is a view partly in end elevation and partly in transverse section taken on the line 2222 of Fig. 2;

. Fig. 23 is a side elevational view of the dirt shields and also showing a fragment of the main side frame;

Fig. 24 is a view partly in plan and-partly in section taken on the irregular line 24-24 of Fig. 23; and

Fig. 25 is a perspective view of the winch for adjusting the dirt shields and a fragment of the main side frame to which it is attached.

It may be here stated that Figs. 1, 2 and 11 are all on the same scale and all of the other figures are on the same scale but on a larger scale than the first noted scale.

1 The trench'excavator, which is the subject matter of my present invention, is a self-containedunit propelled by an internal combustion engine indicated, as an entirety, by the numeral 23 with the exception of its shaft 24. This engine 23' is mounted on the front end portion of a bed 25 forming a part of a novel vehicle which includes two side frames 26, a rear driven axle 21, a front member 28 and two full tracks 29. The rear axle 21 is mounted in an axle housing 3|! having as a part thereof a differential housing 3|. The axle housing 30 extends transversely under the rear end portion of the bed 25 and is rigidly secured thereto. The front member '28 connects the side frames 26 to the bed 25 for limited oscillatory movements in vertical planes.

Each full track 29 includes a multiplicity of hingedly connected cleats 32 in endless arrangement and each cleat 32 has a cog or tooth 33. The full tracks 29 run over driven sprocket wheels 34on the rear axle 21 and idle front sprocket wheels 35 each having a short axle' pneumatic tires may be used place of the I tracks.

The rear axle 21 is driven from the engine 33 by the following connections, to w-it: a long sectional drive shaft 4|, journaled in bearings 42 cn the bed 25, is driven at its front end from the engine shaft 24 by a sprocket chain 43 that runs over triple sprocket wheels 44 and 45 on the engineshaft 2 4; andthey drive shaft 4], respectively. The connections also include, in connection with the. drive shaft 4|, four transmissions, 4,6,and a flexible coupling 48, between each adjacent. pair. of transmissions 45.. The drive shaft 4| has an oblique rear end extension 45; connected thereto by a universal joint 50 and to a short shaft:.5.| by a second universal joint 52, and which short shaft forms a part of the differential mechanism in the housing 3|.

On the rear end. portion of the bed 25areupstanding. mainside frames 53 made up ofangle bars. Each side frame 53- includes an upright bar 54 substantially directly over the-rear axle housing; '30, an oblique bar 55 that extends from the top of the bar 54 forward-1yand downwardly to the bed 25, a short horizontalfbar 5 6 that ex tends rearwardly'from the upper end of the upright bar 54 and an oblique bar 51 that extends from the lower end of the uprightbar 54 to the outer end of the horizontal bar 55. The two side frames 53 are rigidly connected at the rear endportions of the horizontal frame bars-:55 by an angle bar 58, and at the front; end portions of saidbars by-a channel bar 59*.

A si ye r esha t 61 s iqmt a e in beari s 61. on, shor jang belts/6 est d, o e. oblique side frame bars 55 This shovel drive sha t s d v n m hs r e sha t 1' by t following. anima i t wit: a sp ock t... c i runs o e a rocketv heel on the, d ive shaft 4|, between the first and '

thesecond trans missions

4,6,, and asprocket Wheel 65lsecurfedjto a safety clutch 55 on a shaft'G'I spaced above the, drive. shaft 4| andjextending parallel thereto. This shaft 51 is journa led in'bearings 58 ona secondary frame 69. on; the bed 25. On'therear end of the shaft 61 is. a bevel pinion 1 that meshes with a bevel gear. H on a. lower countersliaftflz 'QurnaIed 'in bearings on the side frame bars 55. A sprocket chain 13 runs over a sprocket wheel. 14 on. the lower countershaft 12 arid a sprocket wheel 15011 the never drive heiiifi A shovel boom I6 projects rearwardly from h share; d i eshaft a d me n ede e e r me S i i gm vemen h s' oom; .6, as shown, is a long H-bar. 11;. the, front end pori p ,1 11 3 1. q nin F -f .5 e e end portion of which is shown in Fig. 13. The, majorportion of the section of the boom, 15;; shown in Fig. 12, is provided'with top and botome verat 1.8 and l9; resp ctiv lyr ri dly- 4 flanges of the H-bar 11, see Fig. 16. The flanges of the H-bar I1 and the cover plates 18 and 15 form a box-like structure that extends from the front end of said H-bars rearwardly, see Figs. 12 and 14.

The shovel boom 16, on its front end portion, has a V-shaped head 80, the arms 8| of which diverge forwardly and have on their front ends two-part clamps B2 turnably'mounted on short sleeves 82" on theshoveldrive shaft and support the boom 15 for vertical swinging movement. The sleeves 82' form integral parts of the bearings 6|. Thearms 8| are rigidly and interme atelyconnected by a transverse plate 83. A cas iiig 84 i rigidly secured to the outer face of thepl'tt 83anol has on its inner face a central boss 85, that extends through an aperture in said plate, see Figsfl and 5. This boss 85 has a hexagonal recess in which is rigidly secured a correspondingly formed nut 86. On the inner en por ion of the a ms 8| i on w -Pa sleeve 8] in which the. frontend of the H-bai: T1. is slidably mounted. The members of the sleeve it! are channels and the flanges thereof are in oppq si ng relation andslightly'spaced apart, see 20, 'These members of the sleeve 81 are. connected by ,upper. and lower pairs of nut- Lie-b e 81 at tendth w n n n holes in lugs 89 on said members The n f 9. b 9- i ri d y cu ed n th

bottom plate

1,9,1 at-the transverse center there; of, I for a v purpose which. will. presently appear. e 90, asshown, is a flat plate set edge; vertical plane'and .is downwardly an nea -yams? incl ned. sse o f fan 8; ,T brace 98 "extendslbetween the members; of the sleev 87,, at the'r'ear end portion thereof, and hence, it is v necessary to onset the lower rearmost tie-bolts 88 to afford clearance therefor by means of ,a pair. of fiatbars 9| and two pairsof ribs a'i, The flat bars 9| extend longitudinally and vertically .dgewise under the lower flanges and are rigidly affixed to said sleeve. and fiat ars. T i qw r eermd t a r f s. 9. depend a sre rajeis. n t e. i z an a i d e' re h r gse Figs, 1,8 in A. long adjusting screw 93 havinga, hexagonal head WWhiC tm be t rn d has h i q d, o gagement with thefnut iifi and itsinner end-in pinge he'.clo sed front'endofthe; H.-bar 1 1. Obviously, by turninglthe screw. 93, the H-barv i1, maybe 'endwise adjusted relative to th e boom head 80 to afford a take-up fora shovel conveyor chain, as will presently appear.

A heavy endless shovel conveyor sprocket chain-1 5; r ms; r a re r l. 96 k red, to the shovelri haft; 6% idw y et en. the; clamps 82-on the boom head; arms 8| and a d e-sprocke wh e d s! l p o ket s cur d: ba he lon itudinal; d portions of the W el. 911 iour l d mpai of laterally. s ced: side bars 98 rigidly secured to the outer faces; o herbar "an forms t. r ar e ext ns oi. Q1 e uter s e f. a h. i e] ar...

at the transverse center thereof, is a reinforcing rib that extends substantially the full length of; said sidebar. The ribs 59;, at their rearends,

are forked and extend; to the longitudinal edges,

the side flanges of the H-bar 11 on the outer faces thereof just rearwardly of the rear end of the top cover plate 18 and support saidsprocket wheel above the web of the H-bar 11, see Fig. 2. A guard I02 is secured to the H-bar 11 close to the idle sprocket wheel 91 to prevent sagging of the upper .run of the sprocket chain 95 as it passes onto said sprocket wheel.

A plurality of shovels I03 are secured to certain of the links in the conveyor chain 95 by means of posts I03 spaced equidistantly apart. The lower run of the conveyor chain 95 moves in a guide I04, in the form'of an inverted channel, during its upward travel. This guide I04 is rigidly held suspended from the H-bar 11 by 1 short upright angle bars I05 with their flanges in diverging relation to the longitudinal axis of said bar. These angle bars I05 are used singly except the foremost one, where the sprocket chain 95 leaves the guide I04, which is double with the two angle bars I05 in opposing relation to form a hollow square structure that is held by the brace 90, see Figs. 14 and 18. The shovel sprocket chain guide I04 comprises a pair of angle bars I 06 and a web I01 connecting the same. It will, of course, be understood that a single channel bar may be used in place of the angle bars I06 and web I01. The purpose of the guide I04 is that when the machine is digging, pressure on the shovels I03 will cause the same to push upwardly against the guide I04, as a base of resistance, and act as struts for the posts I03 and thus prevent backward tilting thereof by digging pressure. Tilting of the posts I03 would, in turn, tilt the shovels I03 downwardly and thereby cause the same to dig in and prevent a uniform cut for each shovel I03. This guide I04 also serves the purpose of reinforcing the shovel boom 16 and guides the shovels I03 to make a straight cut.

A grade holder I08 in the form of a stationary beam having a reinforcing truss I08 overlies the shovel boom 95 in the plane thereof, and is rigidly secured to said boom by means of a front mount or anchor I09 and a rear mount H0. The front mount I09 is a fabricated octagonal structure that extends transversely of the shovel boom 16. The top of the front mount I09 is horizontal and there is a gap in the under side thereof. The lower oblique sides of the front mount I09 are rigidly connected by a transverse angle bar III. A short post II2 supports the front mount I09 on the shovel boom 16 and to which boom and the angle bar III said post is I rigidly secured. The grade holder I08, at its front end portion, is rigidly secured and anchored to the front mount I09, as indicated at .3, see Fig. 21. The rear mount H is a rectangular fabricated structure that extends transversely of the shovel boom 16 and its bottom member is a large angle bar II4, the end portions of which extend outwardly of the side members of said mount. A short post II supports the mount IIO on the shovel boom 16 and is rigidly secured to the angle bar H4 and boom 19, see Fig. 22. The grade holder I08 rests on the top of the rear mount H0 and is rigidly secured thereto, as indicatedat II6. Anchor pins II1, for a purpose 'Fig'JZ. The upper -run oftheshovel chain 95 6 extends through the two mounts I09 and H0. The shovel boom is operated by a hydraulic lift II9 that includes a long horizontal cylinder I supported on the angle bar 58 to which it is hinged, as indicated at H9 This cylinder I20 is further supported in a sleeve I III forming a part of a casting I2I on the channel bar 59 and secured thereto by bolts II9. Formed with the'sleeve H9 on each side of the cylinder I20 is a bearing I22, to which bearing and the casting I2I a large directional grooved wheel I23 is journaled. A piston I24 in the cylinder I20'has a piston rod I25 that worksthrough the front end of said cylinder; On the outer end of the piston rod I25 is a bifurcated bearing I26 to which is journaled a large grooved wheel I21. A pair of directional grooved wheels I28 is journaled in bearings I29 on the frame angle bar 58. The pairof wheels I23 and the wheel I21 are horizontally disposed and the wheels I28 are vertically disposed. A cable I30, folded upon itself, extends at its intermediate portion, around the wheel I21 and its folded sections are arranged to run around the pairs of wheels I23 and over the wheels I28 and its end portions are tied to the anchor pins I I1 on the rear mount H0. 'The piston I24 is operated by a fluid delivered by a pump I3I to the cylinder I20 from a supply tank I32 through a tube "I33 in which is interposed a control lever I3I. This pump I3! is driven by the sprocket chain 63.

A crumber I34 including a boom I34 extends rearwardly from the rear mount I I0 between the grade holder boom I08 and the shovel boom 16. This crumber boom I34 includes a pair of laterally spaced square tubular beams I35 pivoted at their front end portions to and between pairs of bearing lugs I36 on the top member of the rear mount [I0 for vertical swinging movement. The two crumber beams I35 are rigidly crossconnected at their fear or free end portions by an angle bar I31. The crumber boom I34 fur ther includes a reinforcing truss I38. Each crumber beam I35 has on its free end a downturned extension I39 that is perpendicular thereto.

The crumber I34 further incluudes a transverse scraper blade I40, the width of which corresponds to the widthof the trench dug by the shovels I03. The shape of the scraper blade I40 conforms to the arcof a circle having its center substantially at the axis of the idle sprocket wheel 91 on the shovel boom 19. This scraper blade I40 is in frontof the crumber beam extension I39, is'rigidly secured at its upper'edge to the crumber beams I35 and said crumber beam extensions I39 afford a base of resistance'for the scraper blade I40 at its lower portion. The purpose of the scraper blade I40 is to smooth the bottom'and sides of the trench and push surplus dirt to the shovels I03.

A pair of rearwardly projecting side plates I4I, between which the crumber beam extensions I39 extend, is rigidly secured to said extensions and the scraper blade I40, as indicated at I42. On the back of the scraper blade I40 is a pair of extension plates I43, to increase the width of said scraper blade'when shovels of a greater width are used in place of the shovels I03. These scraper blade extension plates I43 are adjustably secured to the scraper blade I49 by nut: equipped bolts I44 which extend through holes in said scraper blade and horizontal slots I45 in its extension plates I43, see Figs. 6 and 9. T

The crumber I34 is helddown to its work by bearing plat s I6 to inrease heng le b etyyee x Sides of the trgnq frgm'llli g in thwmie d ii shf BPA' h'e, b 61 16 W1 12; ed o o g A 4 a 9 from the shaft '61 by 2, sp g ke t pam I18 tpjgf; WRQQVFE $.1 39 whs "9.0 h ear end conveyor H4. T pur held f rom tur n while thjsciapiibris l3] alie Sleeve andfbearii g i Qn a i q 9?? h and nut I96. During the upward travel of the shovels I03 around the driven sprocket wheel 96,

-the inner surfaces of said shovels pass just out that may adhere to one of the shovels I03, or

removing a rock or other obstruction therefrom, one or both of the shearing pins I89 will be severed and allow the engaged scraper bar or bars to move with the respective shovel I03. Movement of one Or both of the scraper bars I81 with a shovel I03 will turn one or both of the shafts I90 and thus cause the crank arm or arms I90 to compress one or both of the long springs I91 and the progressive increase in the tension of one Or both of said springs will progressively increase the resistance of the scraper bar or bars I87 to remove an obstruction from a shovel I03. The eccentric pivotal movement of the scraper bars I81, relative to theaxis of the shaft 60 about which the shovels I03 arebeing moved by an engaged obstruction o a shovel I03, will, during extreme rearward movement of said scraper bar or bars, cause the said scraper bars to move shovels I03.

when the machine is digging, the hydraulic lift H9 is free, the crumber slide I51 and its shoe l58 are resting on the bottom of the trench, the

grade holder I 08 at its rear end is supported from the crumber by the ram I46, and said grade holder supports the shovel boom I6, to which it is rigidly secured by the mounts I09 and H with its shovels I03 in digging position. To permit the shovel boom 16 to dig deeper, it is only necessary to release the fluid in the ram cylinder '14? and the weight .of said boom will move the same down.

It will thus be seen that the hydraulic grade holder I08 is used to aid the operator in obtaining a smooth and more accurate grade line in the'bottom of the trench. The shoe I58 is used to impart straight line movement to the shovels I 03.

The shovel boom I6 is lifted out of a trench by means of the hydraulic lift I I9 and held thereby raised above the ground together with the grade holder I08 when the machine is travelling on the road or being reset, etc. The rear end portion of the crumber boom I35 is connected to the grade holder I08 by means of a chain I99. This chain I 99, when the machine is operating, is slack. so as not to interfere with the operation of the ram I46 and the relative adjustments of the crumber and the grade holder I08. When the shovel boom I6 and the grade holder I08 are being lifted and held above the ground by the end portion overlaps an inner ear-202 on a plate 203 and is pivoted thereto, as indicated at 204. The front end portions of the horizontal flanges of the angle bars I and 205 are cut away to clear the

ears

202 and 201 during the raising'or lowering of the dirt shields I84. The plate 203 is rigidly aifixed to the rear end of the bed and supports the dirt shield for vertical swinging movement.

The horizontal brace 205 is secured at one of its end portions to the angle bar20| at its rear end portion by a pair of bolts 206, see Fig. 24. The forward end portion of the vertical flange of the angle bar 205 overlaps an outer ear 201 on the car 20'! and one of apair of horizontally spaced holes 209 in said flange. The two

ears

202 and 201 on the plate 203 are laterally spaced aconsiderable distance apart and hold the brace 205 obliquely to the dirt shield I84. By shifting the bolt 208 from one of the holes 209 to the other, the operative length of the brace 205 may be varied, at will. This adjustment of each brace 205 spaces the dirt shields I 84 at their sions of the dirt shields I84. Each side plate 2 hydraulic lift I I9, the chain I99 holds the crumber suspended from said grade holder.

Referring now in detail to the dirt shields I84, each of which is made of a single sheet of metal on .the winch 2I5.

has an upwardly and outwardly inclined dirtdefiecting top member 2I2 and an upwardly and rearwardly inclined dirt-deflecting top section 2I3. These dirt-deflecting sections 2I2 and 2I-3 direct dirt precipitated from the shovels I03 either back into the trench or onto the crossconveyor I14. The side plates2II are connected at their upper front end portions by a cross-tie angle bar 2I I. Secured to each dirt shield I84 is a forwardly projecting extension 2I4 that closes, the gap between the dirt shield I84 and the respective side plate 2| I.

The dirt shields I84 are simultaneously raised or lowered by means of a winch 2I5 and the following connections, to wit: A rock shaft 2I 6 journaled inbearings 2II on the angle bar 58 has on its right-hand end an arm 2 I8 and On its left-hand end is a lever 2I9 having a short arm 220 that is a duplicate of the arm'2I8 and a long arm 22I. A pair of cables 222 is attached at one of their ends toeyes 223 on the outer end portions of the angle bars 20! and attached at their other ends to the arms 2I8 and 220. A third cable 224'is attached at one of itsends to the long arm 22I and its other end portion is wound The winch 2I5 is mounted on the left-hand angle bar 51 and is provided with a dog 225 and a co-operating ratchet wheel 226 to prevent the winch 2I5 from turning by the pull of the dirt shields I84 thereon, and thus unwind the cable 224 therefrom. Obviously, by operating the winch 2I5, the dirt shields I84 may be raised or lowered, at will.

its front vertical edge portion, by an 'angle bar The'purpose of the dirt shields I84 is to insure reinforced at its entire marginal portion, except j clean shoulders at the top of a trench being dug.

-and,'theside plates'2I I, and which dirt shields and side plates will hold the dirt from falling off said shovels.

The drawings illustrate a commercial form of the trench excavator. but it will be understood that thesame is capable efiagiarge'range efmodification 'withi'n Y the spirit of the invention-herein disclosed and'claimed.

*WhatI claim is: 1. In a machine of the 'class' 'desc'ribed, :en

engine-propelled vehicle, l a rea rwardly projecting shovel boom pivotedat its J front end to the vehicle to swing vertically-2 hydraulic lift 'for raising or lowering the shovelboom,' -shovels mounted onthe' shovelboom totravel an end- 'less course, Zmeans for operating "the'sho'vels 'from the engine, front and rear-mounts on the shovel boom, a-gradeholder beam overlying-the shovel boom and 'the I mounts, said '--grade holder beam being rigidly secured to the -moiints at its front end portion, acrumberineluding a boom extending longitudinally between the shovel boom and the grade'holderbeam andpivoted: at

its from end portion to the *rear mount, said crumb'er boom having a downturnedrear-"extensionyas'craper blade in 'fro'nt of the crumber boom extension, a slide pivotedto the-lower edge portion of the scraperblade, ram controlsbonnecting the grade hol d'er beam "and the crumber and the slide and the-'crumber.

2. In an excavator 'for cutting a trench having a smooth bottom on an accurategrade line, avehicleprovided with a rearwardly 'proj e'cting shovel boom horizontally pivoted at its front end in respecttdthe vehicle'whereby the "rear endof the "shovel boom may be swung vertically, shovels mounted on the shovel boom to travel'an endless course, power means for operating-the shovels, '-a grade l'lolder beam overlying the shovel boomand immovably-se'cu'red to said shovei'booma crumber :boom overlying the shovel boom and positioned between said'shov'el boomandthe grade beam, the crumber boom projectin re'arwar'dly from the vehiclean'd beingh'orizontallypivotally supported at its frontend bythe shovel boom Whereby its'rear'end ma'y be swun vert'ically, the'rear end of the crumber boom being supported upon'a sli'de disposed on anda'da'pte'd to slide over the bottom of the trench 'a scraper blade "carried by the rear end of the 'crumb'er boom and "disposed immediately behind the shovels in their -movement through the rear end of their "course or the number boom and the grade beam' forsupp'or-ting'the' grade beam 'and thereby supporting 5 the rear "end of the 'shovelboom in' respeet to the bottom of the trench.

3. Acons'truction asdefi'nedin'claim 2 wherein, the connection between the Erear endrot the -c'ru'mber boomand the'grade beam islin the form of a longitudinallyextensibleand contractable member, and means for extendingsandz'contra'ct- 'ing said member for vertically selectively "adjusting the rear end of 'the shovel boom in resp'ectrto the bottom of the trench.

*4."A'co'nstruction asdefined in 'claim 2 wl1erein,

' the siipporting engagement' between thet=rear end of the crumbe'r boom and the slideiisatithe forward-{end of thesli'de and is in the'formtofa horiz'on'tall'y disposed piVOtJmeans interoonnectingthe rear end of the slide withrthe crumber boom ata -point above itspivotal connection with thefslide for preventing 'pivotalc movement of the '1 slidein re'spe'ct "to the 'crumber .b oom, saidimeans i being 3 in the form lof a longitudinally.iextensible "and *contraetable device; and means for selectively ex- 12 tlidifi'g'"oriijofttidiitirig -sarYd di iCB IGrSelectively raisi ng and iowermgtne front ex id of the slide.

' 1 5. A construction:asnefinedin tiaim z wherem, the connection between the 7 rear end 03 the 'x'zrumber 'boom and the igr ade beain in the' form of a hydraulicram, means forselectively extend- .ing' andietvacting the ram for r'ai'si'mg and lowering therear'end of the -grade--beam forselectively supportin the rear end of the shovel boom-in respe'e't to' the bottomo'f the trench, the connection -btween' the 'rear end or tlie crumb'er boom and the" slide being in -the form o'f a horiiontal pivot p'ositioned at the front end (iftli'e slidm-ahydraulically operate'd ram interconnecting the i ear end of the slide witntheerumberboomata point :above the connection of the rumber 'boo'm with the slide, andmeans to "'seleo'tively extend and re- 'tra'ct lsaid ram-to: selectively r ai'se -and' lo'wei the 6. A construction 'ais de'fiiiedin cla'im zwhfin, power means is provid'e'd on thevehicI-eand connected t'olthe shoV1 bOOm foriaising it together with i the interconnected :crumber b'oom, g'fade beami gnd slidecfron'i' -the 'tren'ch andIoweriiigsaid f traveL- a'nd a connection between the'rear end of e1ements -int'o the tr'ench,' and means interconnecting' the "grade be'am and cromber boo'm' and operative only when-the parts are raised from tlie trench for supporting th'e crumb'er booin and-its attached-slide fromthegrade beam.

"7. A cons'truotion' as-de'fined inblaim 2 wherein, a. pair of spa'ced: apart'u'pwardly extending mounts are rigidly secured to the shovel boom, the g'fade holder beam ioverlyin'g "ana h'av ing rigid inimovable .connection flwith ssaid mounts, and the i'cruniber' bo'om h'aving l it's pivotal support'o'n one ofsai'd mounts.

'8. A construction as defined in claim- 2 'v'vherein, "a pair'of mounts are rigidly securedto the-shovel I boom and extend upwa'rdly therefrom 'in spac'd relationshineth'e'grade -holder beambverlying and being rigidly immovabl'ysecured to- 'saidflnounts,

- rear end oflthecrumber boom.

-DAN IEL PRZYBYLSKI.

REFERENGES CITED V The followingreferences are of record inth'e file of this patent:

- -UNITED STAT-ES PATENTS